Determination of two neuropeptide growth factor antagonists, [d-Arg,d-Phe,d-Trp,Leu]-substance P and [Arg, d-Trp,N-MePhe]-substance P(6–11), by high-performance liquid chromatography with electrochemical detection

n-MePhe⁸]-substance P(6–11) (G) are currently undergoing preclinical evaluation as potential anticancer agents and clinical trials are planned for G in the near future. A reversed-phase high-performance liquid chromatographic separation has been developed which is both sensitive (limit of detection 250 pg/263 fmol for G; 500 pg/330 fmol for D) and selective, based on electrochemical detection of the two tryptophan residues present in each peptide. Two ion-pairing agents were included in the isocratic mobile phase to eliminate adsorption of the peptides onto the analytical column. Extensive sample clean-up procedures have been developed for plasma, tissue and tumour based on solid-phase extraction. Precision and accuracy of each assay was 91.3 ± 16.9% (between-day) for G and 99.3 ± 16.9% (between-day) for D. The assays were able to detect the intact peptides and a number of their metabolites in plasma, liver and the WX 322 SCLC human xenograft in nude mice for at least 6 hr after administration of therapeutic and pharmacological doses.     

Differential recognition of glycoprotein acceptors by terminal glycosyltransferases

The factors regulating modifications of terminal ß-Galresidues in lactosaminyl (Gaiß     

Rodents infected with Schistosoma mansoni produce cytolytic IgG and IgM antibodies to the Lewis x antigen

Schistosoma mansoni is a blood fluke that produces glyco-conjugatescontaining the Lewis x antigen (Le^x) Galß1